含浮环式挤压油膜阻尼器结构与动力特性研究

发布时间：2018-07-28 14:59

【摘要】：针对传统挤压油膜阻尼器挤压油膜高度非线性的问题，本文对新型含浮环式挤压油膜阻尼器（FSFD）及其转子系统动力特性进行了研究，研究成果对航空发动机的减振有重要意义。主要研究成果和相关结论如下：（1）基于广义雷诺方程、壁面摩擦方程和Hirs整体流动理论，，推导了含浮环式挤压油膜阻尼器内、外层油膜的稳态雷诺方程。根据内、外层油膜压力平衡关系，建立了FSFD模型，为FSFD动力特性分析提供了较好的理论基础。（2）根据本文的理论模型，基于有限差分法编写了计算程序，研究分析了含浮环式挤压油膜阻尼器结构和油膜参数对其特性的影响。研究表明：在偏心率越小、油膜宽度越宽、油膜间隙越大时，FSFD的等效阻尼越大；等效油膜阻尼随着供油温度的升高而减小。与传统挤压油膜阻尼器相比，本文的FSFD明显改善了非线性特性。（3）考虑到油膜力的非线性，建立FSFD-单转子模型，仿真计算了其临界转速、稳态不平衡响应、非协调进动响应和突加不平衡响应。计算结果表明：含FSFD的转子系统稳态不平衡响应明显小于不含FSFD的转子系统，表明FSFD减振效果较好；计算了不平衡量、转速、浮环质量、滑油粘度、油膜宽度、油膜间隙对FSFD-转子系统的非协调进动的影响，由转子响应分岔图可以看出，随着不平衡量的减小、滑油粘度系数的增加、浮动环油膜间隙的减小、油膜宽度的增加，转子的非协调进动响应范围逐渐减小，选择合适的浮动环质量可以抑制FSFD-转子系统的非协调进动响应；仿真计算了转速、弹支刚度及浮环质量对FSFD-转子系统突加不平衡响应的影响，FSFD在抑制突加不平衡响应方面明显强于传统挤压油膜阻尼器。（4）利用双向激励试验器，对FSFD动力特性进行了试验验证，研究了激振力大小、油膜间隙、供油压力及油膜宽度对油膜压力的影响。试验结果与理论计算结果具有很好的一致性，由此证明了本文模型的正确性，对工程应用有很好的指导意义。本文研究内容对FSFD及FSFD-转子系统动力特性的研究提供了很好的理论基础。有很好的工程应用前景。
[Abstract]:Aiming at the problem of high nonlinearity of squeeze film in traditional squeeze film damper, the dynamic characteristics of (FSFD) and its rotor system with floating ring type squeeze film damper are studied in this paper. The research results are of great significance to the vibration reduction of aero-engine. The main research results and related conclusions are as follows: (1) based on the generalized Reynolds equation, wall friction equation and Hirs flow theory, the steady-state Reynolds equation of the outer layer oil film in the squeeze film damper with floating ring is derived. According to the pressure balance relationship between the inner and outer layers of oil film, the FSFD model is established, which provides a good theoretical basis for the analysis of the dynamic characteristics of FSFD. (2) according to the theoretical model of this paper, the calculation program is compiled based on the finite difference method. The influence of the structure and the film parameters of the squeeze film damper with floating ring on its characteristics was studied. The results show that when the eccentricity is smaller, the width of oil film is wider and the gap of oil film is larger, the equivalent damping of FSFD increases, and the equivalent oil film damping decreases with the increase of oil supply temperature. Compared with the traditional squeeze film damper, the FSFD in this paper improves the nonlinear characteristic obviously. (3) considering the nonlinearity of the oil film force, the FSFD-single rotor model is established, and the critical speed and the steady state unbalance response are simulated and calculated. Uncoordinated precession response and sudden unbalanced response. The results show that the steady-state unbalance response of the rotor system with FSFD is obviously smaller than that of the rotor system without FSFD, which indicates that the FSFD has better vibration absorption effect, and calculates the unbalance, the speed, the mass of floating ring, the viscosity of oil and the width of oil film. The effect of oil film clearance on the uncoordinated precession of FSFD-rotor system can be seen from the rotor response bifurcation diagram. It can be seen that with the decrease of unbalance, the increase of oil viscosity coefficient, the decrease of oil film clearance of floating ring, and the increase of oil film width, The uncoordinated precession response range of the rotor decreases gradually, and the uncoordinated precession response of the FSFD-rotor system can be restrained by choosing the appropriate floating ring mass. Effect of elastic stiffness and floating ring mass on the sudden unbalance response of FSFD-rotor system FSFD is obviously better than the conventional squeeze film damper in suppressing the sudden unbalance response. (4) A bidirectional excitation tester is used. The dynamic characteristics of FSFD were tested and the effects of exciting force, oil film clearance, oil supply pressure and oil film width on the film pressure were studied. The experimental results are in good agreement with the theoretical results, which proves the correctness of the model in this paper and has a good guiding significance for engineering application. This paper provides a good theoretical basis for the study of dynamic characteristics of FSFD and FSFD-rotor systems. It has a good prospect of engineering application.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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